Neighborhood Disadvantage, Built Environment, and Breast Cancer Outcomes: Disparities in Tumor Aggressiveness and Survival.

Background: Breast cancer disparities persist globally, with growing evidence implicating neighborhood and built environmental factors in disease outcomes.

Methods: This study investigates the associations between neighborhood disadvantage, environmental exposures, and breast tumor characteristics and survival among 3041 stage I-III breast cancer patients treated at the University of Virginia Comprehensive Cancer Center (2014-2024). Neighborhood disadvantage was assessed via the Area Deprivation Index (ADI), while environmental exposures included PM2.5, green space (NDVI), and food indices (modified retail food environment index (mRFEI), retail food activity index (RFAI)). Multivariable regression and Cox models adjusted for demographic, socioeconomic, and clinical covariates were employed.

Results: A higher ADI score was associated with aggressive tumor characteristics, including advanced stage (Odds Ratio (OR) = 1.06, 95% Confidence Interval (CI):1.01-1.11), poor differentiation (OR = 1.07, 1.01-1.15), ER-negative status (OR = 1.06, 1.01-1.12), and triple-negative breast cancer (TNBC) (OR = 1.08, 1.02-1.16), as well as younger diagnosis age (β = -0.22, -0.36 to -0.09). PM2.5 exposure was correlated with advanced tumor stage (OR = 1.24, 1.09-1.40 for stage III) but paradoxically predicted improved survival (Hazard Ratio (HR) = 0.71, 0.63-0.82). The food environment indices showed subtype-specific survival benefits: higher mRFEI and RFAI scores were linked to reduced mortality in ER-negative (HR = 0.45, 0.23-0.85 and HR = 0.61, 0.38-0.97) and TNBC (HR = 0.40, 0.18-0.90 and HR = 0.48, 0.26-0.87) patients. NDVI scores exhibited no significant associations.

Conclusion: Our findings underscore the dual role of neighborhood disadvantage and the built environmental in breast cancer outcomes. While neighborhood disadvantage and PM2.5 exposure elevate tumor aggressiveness, survival disparities may be mediated by other factors. Improved food environments may enhance survival in aggressive subtypes, highlighting the need for integrated interventions addressing socioeconomic inequities, environmental risks, and nutritional support needs.